(EN) The invention relates to a method for preparing an A-B-C2 or A2-(Dx, E1_x)-C4 absorber thin film for photovoltaic cells where 0 ≤ x ≤ 1, A is an element or mixture of elements selected within Group 11, B is an element or mixture of elements selected within Group 13, C is an element or mixture of elements selected within Group 16, D is an element or mixture of elements selected within Group 12, and E is an element or mixture of elements selected within Group 14. Said method includes: a step (S1) of electrochemically depositing oxide from elements selected from among Groups 11, 12, 13, and 14, a step (S2) of annealing in a reducing atmosphere, and a step (S3) of supplying an element from Group 16.